It is proposed to study our kinetic and mechanistic studies pertaining to enzymic hydrolyses with particular emphasis on erythrocyte carbonic anhydrases (carbonate hydrolyases EC 4.2.1.1). Our earlier work has appeared in Biochemistry, J. Amer. Chem. Soc., J. Phys. Chem., J. Org. Chem., and Science. Our work exploits the remarkable versatility of carbonic anhydrase both with respect to its substrates and the variety of reactions which it catalyzes. Work in progress uses Zn(II)-, Co(II)-, Mn(II)-, Cd(II)-c and Ni(II)- carbonic anhydrases and exploits temperature jump, stopped flow, NMR, and ORD/CD techniques in the study of the elementary enzymic steps and their combination in the overall mechanism of hydration-dehydration in both H2O and D2O. Other developments concern: (a) studies of model systems for rate acceleration and specificity; (b) comparative studies of apo- and native enzyme; (c) partial denaturation and reactivation; (d) sulfonamide inhibition; (e) active site modification; (f) enzyme interaction with proteins and nucleic acids; (g) comparative studies of mammalian vs plant enzyme. BIBLIOGRAPHIC REFERENCES: Electrophilic Catalysis by Nucleophilic Substitution and Elimination. VIII. Kinetics and Mechanism of Reaction of tert-Amyl and 1-Adamantylcarbinyl Halides with Silver Salts in Acetonitrile, Y. Pocker and W.-H. Wong, J. Am. Chem. Soc., 97, 7105 (1975). Mechanism of Aminolysis of delta-lactones. Kinetic Behavior of Tri-D-methyl-2-deoxyglucono-delta-lactone, Solvent Deuterium Isotope Effects, and Transition State Characterization, Y. Pocker and Edmond Green, J. Am. Chem. Soc., 98, Sept. 29 issue.